Characterizing wood furnish is important in the manufacture of engineered wood products including oriented strand board (OSB) and fibreboard.
For example, measuring the level of fines in wood furnish is important for optimizing OSB production. Fines are small wood particles that are generated as a byproduct during stranding. Fines are too small to be useful in OSB production. In drier woods, such as mountain pine beetle infested wood, fines can account for 5% to 40% of furnish after stranding. High fine levels greatly affect the volume and value recovery from raw wood. The percentage of fines generation is therefore a key indicator used by mills for gauging the production of quality of furnish in OSB production. It is estimated that for an average-sized mill, a 1% improvement in wood recovery by reducing fines would result in wood cost savings on the order of hundreds of thousands of dollars per year.
A number of variables affect fines generation including characteristics of the wood (e.g. species, moisture content, temperature, pest damage) and operating conditions of the strander (e.g. wood alignment, rotation speed, cutting angle, sharpness of cutting and scoring knives).
At present, the level of fines in furnish is typically measured by manual sampling and screening. This method is very slow and does not provide “real time” measurements. Fines generation is highly variable and significant changes can occur over very short time spans. Mill operators limited to manual sampling and screening are unable to make timely and effective adjustments in response to changes to the level of fines in wood furnish.
It is desirable to provide systems and methods that provide operators with real time, accurate measurements of wood furnish characteristics such as the level of fines.